Imaging neurodegeneration in the mouse hippocampus after neonatal hypoxia–ischemia using oscillating gradient diffusion MRI. Issue 3 (4th October 2013)

• Record Type: Journal Article
• Authors: Aggarwal, Manisha; Burnsed, Jennifer; Martin, Lee J.; Northington, Frances J.; Zhang, Jiangyang
• Is Part Of: Magnetic resonance in medicine. Volume 72:Issue 3(2014:Sep.)
• Page Start: 829
• Page End: 840
• Publication Date: 2013-10-04
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24956
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24956-sec-0001" sec-type="section"> <title>Purpose</title> <p>To investigate if frequency‐dependent contrasts using oscillating gradient diffusion MRI (dMRI) can detect hypoxia–ischemia (HI) ‐induced neurodegeneration in the neonatal mouse hippocampus.</p> </sec> <sec id="mrm24956-sec-0002" sec-type="section"> <title>Methods</title> <p>Pulsed‐ and oscillating‐gradient dMR images (at 50, 100, and 150 H<sc>z</sc>) were acquired from postmortem fixed brains of mice exposed to neonatal HI using the Rice‐Vanucci model. MRI data were acquired at 1, 4, and 8 days following HI, and compared with histological data from the same mice for in situ histological validation of the MRI findings.</p> </sec> <sec id="mrm24956-sec-0003" sec-type="section"> <title>Results</title> <p>The rate of change of apparent diffusion coefficient with gradient frequency (Δ<sub>f</sub>ADC) revealed unique layer‐specific contrasts in the neonatal mouse hippocampus. Δ<sub>f</sub>ADC measurements were found to show a significant decrease in response to neonatal HI injury, in the pyramidal (Py) and granule (GrDG) cell layers compared with contralateral regions. The areas of reduced intensity in the Δ<sub>f</sub>ADC maps corresponded to regional neurodegeneration seen with H&E and Fluoro‐Jade C stainings, indicating that alterations in Δ<sub>f</sub>ADC contrasts are sensitive to early microstructural changes due to HI‐induced neurodegeneration in the studied regions.</p> </sec> <sec id="mrm24956-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The findings show that the frequency‐dependence of ADC measurements with oscillating‐gradient dMRI can provide a sensitive contrast to detect HI‐induced neurodegeneration in neuronal layers of the neonatal mouse hippocampus. Magn Reson Med 72:829–840, 2014. © 2013 Wiley Periodicals, Inc.</p> </sec> </abstract>